From version 4.0.5 you can set Meta Data for any page in CMS, for example, Home Page, Contact Us, Forum, Site Map, Helpdesk etc. Also you can set up
general Meta settings that would apply to all products, articles, categories or custom pages (unless you specify individual Meta Data on item's Edit page)
via such pages as Products Listing Page, Products Details Page, Articles Listing Page, Aricles Details Page and Custom Pages.

Settings:

Go to CMS > Pages Layouts click on some page and then click on 'META DATA' link next to Layout selection. Then click 'Save'
and 'Update'.